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[libc++] Drop the unrepresentative search_n benchmark (#184783)

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This benchmark isn't very good at benchmarking `search_n`, since a good
`search_n` implementation can go through it in ~10 perfectly predictable
steps. We can drop it to avoid spending unnecessary resources. This also
fixes that the two benchmark sets have identical names.

Fixes #183832
This commit is contained in:
Nikolas Klauser 2026-03-10 10:40:12 +01:00 committed by GitHub
parent 2eb69c602f
commit 15bcae5e3b
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1 changed files with 0 additions and 36 deletions
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36
libcxx/test/benchmarks/algorithms/nonmodifying/search_n.bench.cpp
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@ -31,42 +31,6 @@ int main(int argc, char** argv) {
});
};
// Benchmark {std,ranges}::search_n where the needle is never found (worst case).
{
auto bm = []<class Container>(std::string name, auto search_n) {
benchmark::RegisterBenchmark(
name,
[search_n](auto& st) {
std::size_t const size = st.range(0);
using ValueType = typename Container::value_type;
ValueType x = Generate<ValueType>::random();
ValueType y = random_different_from({x});
Container haystack(size, x);
std::size_t n = size / 10; // needle size is 10% of the haystack
for ([[maybe_unused]] auto _ : st) {
benchmark::DoNotOptimize(haystack);
benchmark::DoNotOptimize(n);
benchmark::DoNotOptimize(y);
auto result = search_n(haystack.begin(), haystack.end(), n, y);
benchmark::DoNotOptimize(result);
}
})
->Arg(32)
->Arg(1024)
->Arg(8192);
};
// {std,ranges}::search_n
bm.operator()<std::vector<int>>("std::search_n(vector<int>) (no match)", std_search_n);
bm.operator()<std::deque<int>>("std::search_n(deque<int>) (no match)", std_search_n);
bm.operator()<std::list<int>>("std::search_n(list<int>) (no match)", std_search_n);
// {std,ranges}::search_n(pred)
bm.operator()<std::vector<int>>("std::search_n(vector<int>, pred) (no match)", std_search_n_pred);
bm.operator()<std::deque<int>>("std::search_n(deque<int>, pred) (no match)", std_search_n_pred);
bm.operator()<std::list<int>>("std::search_n(list<int>, pred) (no match)", std_search_n_pred);
}
// Benchmark {std,ranges}::search_n where the needle almost matches a lot.
{
auto bm = []<class Container>(std::string name, auto search_n) {